This invention relates to fuel supply apparatus for an internal combustion engine and, in particular, to method and apparatus for supplying vaporized fuel in addition to conventionally carburetted fuel for promoting engine efficiency.
It is now well known that conventionally produced internal combustion engines are inefficient in the sense that in the exhaust therefrom there is present unburned or partially burned fuel. In response to this situation, and often mandated by government regulation, devices for eliminating these unburned or partially burned particles from automotive exhaust have been introduced. This generally involves the use of filtering devices which, at best, are partially effective and often cause a significant reduction in the performance of the engines to which they are attached. Generally, in order to overcome the deficiencies of the filtering devices, it has been necessary to adjust the engines in question to operate on a "leaner" fuel-air mixture. Again, this is only a partial solution and has resulted in an overall decrease in the efficiency of operation of internal combustion engines.
It is known that atomization of liquid fuel beyond the amount realized by utilization of a standard automotive carburetor improves the efficiency and operation of the leaner-burning engines which must be used to reduce the amount of pollutants emitted therefrom. Improved atomization enables leaner fuel mixtures to be utilized because the mixture, improved by atomization, promotes more complete combustion of the fuel-air mixture thereby promoting easier starting of the engine, leaner and shorter duration of choke settings and more satisfactory operation of cold engines. These desirable results can be achieved even in the presence of the leaner mixture settings which, as mentioned, must now be used.
While, as pointed out hereinabove, it is desirable to as completely as possible atomize the fuel in the fuel-air mixture, conventional carburetor-type fuel supply installations which are now generally present do not accomplish this result. In the conventional carburetor, fuel is atomized by a venturi-type negative pressure. The fuel particles resulting from any atomization taking place in the conventional carburetor are relatively large in diameter so that they may remain and attach themselves to the inner walls of an intake passage. This, of course, alters the prescribed fuel-air ratio. This problem would not be present if the fuel particle size were reduced, as by atomization. In any event, carburetor-equipped internal combustion engines, as are presently available, are not equipped to provide for such atomization, and they cannot be so equipped without expensive and relatively complex modification.
In view of the foregoing, it is an object of this invention to provide means and method for supplementing the carburetted fuel supply in a conventional internal combustion engine with an atomized fuel supply in order to increase the efficiency of operation of the engine.
Another object of this invention is to provide means and method for efficiently providing a vaporized fuel supply on demand to an internal combustion engine during operation of the engine.
Still another object of this invention is to provide a supplementary fuel supply for the conventional carburetted fuel supply in an internal combustion engine, but one which does not increase the magnitude of the total fuel consumption of the engine.
A further object of this invention is to provide means and method by which the operating efficiency of an internal combustion engine can be increased while still reducing the air pollutants it emits.